The SmoothTalker Mobile X1 is a dual-band cell phone booster that enhances your 4G, 3G and 2G signals. It has an amplifier with a 50 dB maximum gain, which is the highest gain allowed by the FCC. When you combine this with a high-gain 14-inch outside antenna, you increase your call quality, signal reliability and cell phone battery life, because your phone doesn't have to constantly search for a signal. For these reasons, it is one of the best cell phone boosters available.

The Mobile X1 is one of the few cell signal boosters that's compatible with 4G, 3G and 2G networks. However, this is limited to just two frequency bands: the 800MHz and 1,900MHz bands. These are the standard frequencies that most cellular frequencies are broadcast on, but the best cell phone boosters cover up to five frequency bands. The lack of a 700MHz frequency band limits your access to much of the 4G networks available. For example, Verizon Wireless and AT&T broadcast 4G frequencies on the 700MHz band, while only Sprint broadcasts on the 800MHz band.

The amplifier has a max gain of 50 dB. This is the most powerful amplifier allowed by law for a cell phone booster designed for cars. It's powerful enough to provide a wireless coverage area that's adequate for cars, trucks, vans and RVs. In addition, it automatically adjusts the gain according to the outside signal. This protects your phones from a signal overload by lowering the gain when the outside signal is strong and only amplifying it when the signal becomes weak.

The SmoothTalker Mobile X1 features a wireless design, which means that there are six components to consider during installation – the outside antenna, inside antenna, amplifier box, two coax cables and a car charger. The outside antenna has a magnetic base that allows you to remove it easily without damaging your paint.

It also comes with a 15-foot coax cable that leads from the outside antenna to the amplifier, which makes it ideal for van and RV installation, though it just as easily installs into cars and trucks. The inside antenna attaches to the amplifier with a 4-foot cable, which is considerably short compared to most cell phone boosters. This simply means that you have to install the cell phone signal amplifier closer to the inside antenna, which isn't an issue if you install it under your seat. For comparison, the longest coax cable for an inside antenna is 14 feet. The second longest is 10 feet.

The outside antenna is the longest one we reviewed at 14 inches. It has an average forward gain of 5 dBi, which, along with the SureCall TriFlex2Go, is among the highest available. This means that it has excellent range for rural areas where you're far from cell phone towers, as opposed to areas where physical objects like buildings, hills and mountains get in the way of the cell tower. For areas like that, you should look at the weBoost Drive 4G-M.

The biggest downside to the SmoothTalker Mobile X1 is the lack of support. While it has an industry-leading three-year warranty that protects against manufacturer defects, there are very few resources to help you with the product. Unlike its competitors, SmoothTalker doesn't offer a live chat feature, so you have to call or email the support staff. You can't download manuals, read a blog about its technology or reference a FAQs page for quick answers. The website is difficult to navigate. You might stumble upon a PDF article here and there that vaguely explains cell phone boosting concepts or antenna myths, but never will you find anything that addresses SmoothTalker's products or any of the issues you might experience.

The SmoothTalker Mobile X1 is one of the best cell phone boosters because it combines the most powerful amplifier allowed by law with a 14-inch high-gain antenna and 4G compatibility, though this is limited to the 800MHz and 1,900MHz frequency bands. It has the wireless range to cover any car, truck, van or RV. However, the customer support is severely lacking in resources.